This invention relates to a process for preparing (2,2,2-trihalo-1,1-dihydrocarbylethoxy)trihydrocarbylsilanes (hereinafter referred to as Wang compounds).
By subjecting Wang compounds to mildly acidic conditions, they may be converted to their corresponding trihalomethyl-substituted hydroxyl-containing compounds which are useful intermediates for the preparation of .alpha.-substituted acid chlorides.
W. Reeve, in Synthesis, 131 (1971) discloses applications adapted to the use of trichloromethyl carbinol compounds. In particular, the reference describes a wide variety of reactions between trichloromethyl carbinols and reactive nucleophiles such as to prepare .alpha.-substituted acid chlorides, amino acids and mercapto acids.
Previous techniques for the preparation of Wang compounds include U.S. Pat. No. 4,375,548. The process of U.S. Pat. No. 4,375,548 disadvantageously requires elevated reaction temperatures.
Previously known techniques for the preparation of aryl-(trichloromethyl)carbinols also include the reaction of aromatic hydrocarbons with trichloroacetaldehyde in the presence of a Lewis acid or the reaction of arylmagnesium bromide with trichloroacetaldehyde.
It is also known to prepare aryl-(trichloromethyl)carbinols and alkyl-(trichloromethyl)carbinols by the reaction of carbonyl compounds with chloroform in the presence of caustic and a phase-transfer catalyst such as a quaternary ammonium salt.
Additional processes include electrochemical reduction of carbon tetrachloride and subsequent reaction of the carbon trichloride anions with electrophilic aldehydes. In the presence of hydrogen-containing solvents, e.g., chloroform, the intermediate reaction product abstracts a proton from the solvent, thereby preparing the desired trichloromethyl-substituted carbinol compound.
These processes all disadvantageously form stoichiometric by-products. It would be desirable to have a process to form Wang compounds without forming a stoichiometric amount of one or more by-products.